haskell, fp, ocaml, elixir/erlang, f#, racket, common lisp/scheme [for general enlightment] to broaden your horizons monads, type-classes, pattern matching to

haskell, fp, ocaml, elixir/erlang, f#, racket, common lisp/scheme [for general enlightment] to broaden your horizons monads, type-classes, pattern matching to get out of the imperative mindset from cpp, java,python, ruby [to be clear avoid java, cpp,python, ruby] c is needed for performance, elixir/erlang for concurrency/parallelism, haskell/racket/common lisp for enlightenment